On-line measurement of contaminant level in lubricating oil

Abstract

A measurement apparatus determines contaminant level of oil by qualitatively measuring the light intensity after the light has transmitted through an oil sample. The apparatus comprises light emitting means for generating light to be provided to the oil sample, a container for storing the oil sample, the container being displaced from the light emitting means by a predetermined distance, light receiving means for detecting the intensity of light transmitted through the oil sample, the receiving means being displaced from the container by a predetermined distance, first light conveyance means for conveying the light generated by the light emitting means as coherent light to the oil sample, second light conveyance means for conveying the light transmitted through the oil sample to the light receiving means, wherein the characteristics of the light emitting means and the light receiving means are controlled so that they do not vary depending on the temperature of the oil sample.

Dependencies are inferred from the claim text.